Cyanoalkylamino-amido benzophenones

ABSTRACT

The present invention relates to pharmacologically valuable new benzophenone derivatives having a pronounced sedative action on the central nervous system and some of which also possess musclerelaxing and aggression-inhibiting properties. These new derivatives have the structural formula     AND THEIR ACID ADDITION SALTS, IN WHICH R1 and R2 are substituents selected from the group consisting of hydrogen, saturated and unsaturated alkyl groups having 1-4 carbon atoms; R3 is a substituent selected from the group consisting of -CN, CONH2, -COOCH3, -COOC2H5, -COOH, and -COOMe, where Me is a metallic cation; n is an integer selected from 1 and 2; and m is an integer selected from 1,2, and 3, and wherein the rings A and B may be substituted, ring A being substituted preferably with a halogen such as chlorine or with nitro, trifluoromethyl, methyl, methoxy or methylmercapto, preferably in the 5 position, and ring B being preferably substituted in the 2&#39;&#39; position with chlorine or fluorine. The radicals R1 and R2 preferably signify hydrogen or a methyl group, or a n-butyl group in the case of Ring B. The metal cation Me is preferably a pharmacologically acceptable metal cation, as for example sodium, potassium, calcium or ammonium. Compounds represented by the above structural formula may be produced by reacting a compound represented by the formula WITH A COMPOUND HAVING THE FORMULA Y-CmH2m-R3, one of X and Y signifying the substituent R2-NH- and the other signifying a halogen atom, preferably a bromine or chlorine atom, so as to form the above specified benzophenone derivative with the elimination of H-Hal, R1, R2, R3, n and m being as defined above, and the rings A and B being optionally substituted as discussed above. The hydrogen halide which is eliminated is advantageously bound by the addition of an acid-binding agent, as for example, a molar excess of the amine used in the reaction or, for example, triethylamine, dimethylaniline, potassium or sodium carbonate or sodium bicarbonate. The reaction is carried out in a suitable solvent, preferably at an elevated temperature, typically the reflux temperature of the solvent used.

United States Patent 1 Greve et a1.

[ CYANOALKYLAMINO-AMIDO BENZOPHENON ES [75] Inventors: Heinz Gunter Greve; Klaus Resag,

both of Frankfurt am Main-Fechcnheim, Germany [73] Assignee: Cassella Farbwerke Mainkur Akt.,

Frankfurt am Main, Germany 22 Filed: May 8,1973

211 Appl. No.: 358,455

[30] Foreign Application Priority Data May 12, 1972 Luxembourg 65340 [52] US. Cl 260/465 D; 260/471 A; 260/516;

260/517; 260/518 A; 260/518 R; 260/519; 260/558 A; 424/304; 424/309; 424/319; 424/324 [51] Int. Cl. C07c 121/78 [58] Field of Search 260/465 D [56] References Cited UNITED STATES PATENTS 2,855,428 10/1958 Singer et a1 260/4655 3,455,985 7/1969 Stcrnbach et a1 260/465 3,772,371 11/1973 Tachikawa et a1 260/465 X Primary Examiner-Lewis Gotts Assistant Examiner-Dolph H. Torrence Attorney, Agent, or Firm-Francis M. Crawford [5 7] ABSTRACT The present invention relates to pharmacologically valuable new benzophenone derivatives having a pronounced sedative action on the central nervous system and some of which also possess muscle-relaxing and aggression-inhibiting properties. These new derivatives have the structural formula [451 time 10, 1975 and their acid addition salts, in which R, and R are substituents selected from the group consisting of hydrogen, saturated and unsaturated alkyl groups having 1-4 carbon atoms; R is a substituent selected from the group consisting of CN, -CONl-l COOCH -COOC l-l COOH, and COOMe, where Me is a metallic cation; n is an integer selected from 1 and 2; and m is an integer selected from 1,2, and 3, and wherein the rings A and B may be substituted, ring A being substituted preferably with a halogen such as chlorine or with nitro, trifluoromethyl, methyl, methoxy or methylmercapto, preferably in the 5 position, and ring B being preferably substituted in the 2' position with chlorine or fluorine. The radicals R and R preferably signify hydrogen or a methyl group, or a nbutyl group in the case of Ring B.

Compounds represented by the above structural formula may be produced by reacting a compound represented by the formula N C0 C 11 X n ...n

n 110 v A with a compound having the formula YC,,,H ,,,R one of X and Y signifying the substituent R -Nl-l and the other signifying a halogen atom, preferably a bromine or chlorine atom, so as to form the above specified benzophenone derivative with the elimination of l-ll-lal, R R R n and m being as defined above, and the rings A and B being optionally substituted as discussed above. The hydrogen halide which is eliminated is advantageously bound by the addition of an acid-binding agent, as for example, a molar excess of the amine used in the reaction or, for example, triethylamine, dimethylaniline, potassium or sodium carbonate or sodium bicarbonate. The reaction is carried out in a suitable solvent, preferably at an elevated temperature, typically the reflux temperature of the solvent used.

8 Claims, No Drawings 1 CYANOALKYLAMINO-AMIDO BENZOPHENONES The invention relates to pharmacologically valuable new benzophenone derivatives of the general formula and their acid addition salts, in which R and R signify hydrogen or a saturated or unsaturated alkyl radical with 1 to 4 carbon atoms,

R;, signifies a -CN, -CONI-I COOCH COOC H COOI-I or COOMe group, Me signifying a metal cation,

n is l or 2,

m is l, 2 or 3, and the rings A and B may be substituted.

Preferred substituents for the ring A are halogen, especially chlorine, nitro, trifluoromethyl, methyl, methoxy or methylmercapto, and substitution is preferably in the 5 position, and preferred substituents for the ring B are fluorine or chlorine, substitution preferably being at the 2' position. The radicals R and R preferably signify hydrogen or a methyl group, or an n-butyl group in the case of R The metal cation Me is preferably a pharmacologically acceptable metal cation, for example the sodium, potassium, ammonium or calcium The invention also extends to processes for the production of compounds of the general formula I.

Compounds of the general formula I may be produced by reacting a benzophenone derivative of the general formula II n 2:1 spam 'r. I./

with a compound of the general formula III Ill one of X and Y signifying the radical R NH and the other signifying a halogen atom, preferably a bro mine or chlorine atom, so as to form a compound of the general formula I with the elimination of H-Hal, R R R n and m being ad defined above, and the rings A and B being optionally substituted as discussed above. The hydrogen halide which is eliminated is advantageously bound by the addition of an acid-binding agent. Suitable acid-binding agents are a molar excess of the amine used in the reaction or, for example, tri ethylamine, dimethylaniline, potassium or sodium carbonate or sodium bicarbonate. The amine can also be employed in the form of an acid addition salt, in which case it is then necessary in order to liberate the amine to use a further mole of the acid binding agent. The reaction is carried out in a suitable solvent, preferably at an elevated temperature, typically the reflux temperature of the solvent used. Examples of suitable solvents are ethers, for example dioxane, hydrocarbons, for example benzene, toluene or xylene and ketones, for example acetone or methylisobutylketone. It may be advantageous to carry out the reaction under an inert atmosphere, for example under nitrogen.

Starting compounds of the general formula II, in which X signifies a halogen atom, can easily be produced from aminobenzophenones of the general formula IV by reaction with a halogenacyl halide of the general formula V ll Hal C C H Hal The initial compounds of the general formula II, in which X signifies the radical R NH, can be obtained by reacting a compound of the general formula Ila with an amine of the general formula VI R NI-I The reaction is preferably carried out at a temperature between 5 and 50 with a reaction time of from a few hours up to several days, advantageously in a suitable solvent.

Those compounds of the general formula I, in which m signifies 2 or 3 and R R R and n are as defined above, may be produced by an addition reaction between a benzophenone derivative of the general formula II, in which X signifies R NH, and a compound containing an aliphatic double bond and of the general formula VI! in which m means the number 2 or 3. The reaction is preferably carried out in a suitable solvent at room temperature or elevated temperature. Examples of suitable solvents are alcohols, ethers, ketones, hydrocarbons and acid amides.

Those compounds of the general formula I in which R is CN and is in the a position in relation to the amino group of the side chain can also be prepared by reacting a compound of the general formula II, in which X signifies the radical R- NI-I, with am aldehyde or ketone of the general formula VIII C l-I O VIII and hydrocyanic acid or an alkali metal cyanide, preferably potassium cyanide. It is normally advantageous first to add the aldehyde or ketone of general formula VIII to an aqueous sodium bisulphite solution as in a Knoevenagel-Bucherer reaction, then to introduce the compound of general formula II, and finally a concentrated aqueous solution of alkali cyanide. The reaction is carried out at room temperature or slightly elevated temperature.

Compounds according to the invention in which R signifies a carbmethoxy or carbethoxy group can be converted by saponification into compounds according to the invention in which R, is COOH or by ammonolysis into compounds according to the invention in which R is CONH Compounds according to the invention in which R is COOI-l may be used to prepare the corresponding salts COOMe.

Normally compounds according to the invention are oily substances which provide crystalline acid addition salts.

The compounds of the general formula I and their pharmaceutically acceptable salts are characterised bv valuable pharmacological properties, especially a pronounced sedative action on the central nervous system. Some of these compounds also possess muscle-relaxing and aggression-inhibiting properties. The compounds of the general formula I their 1.11 fer-.tically acceptable salts are therefore valuable pharmaceutical products which can be used as medicaments in the form of pharmaceutical preparations. The pharmaceutical preparations can be put up, for example, as tablets, suppositories, capsules, emulsions or suspensions in a known manner by the use of pharmaceutically acceptable diluents or carriers which do not react with the compounds. As diluents or carriers it is possible to use any substance which is suitable for the purpose in mind, for example talcum, starch, vegetable oils or petroleum jellies. If desired the pharmaceutical preparations may also contain other therapeutically active substances.

The pharmacological investigation of the sedative action on the central nervous system was carried out using the climbing tests on albino mice described by P. K KNEIP: Arch. int. pharmacodyn 126, 238 (1960) and R. DOMENJOZ and W. THEOBALD: Arch. int. pharmacodyn 120, 450 (1959).

In the table which follows, the results of the pharmacological investigations carried out are summarised. In the last table under the heading Sedative action there is given the percentage of the experimental animals which no longer take up the normally readily assumed climbing work.

Compound Dose mg/kg p.o.

LD (mouse) Sedative action 2-( 5-Cyano-N,4-dimethyl- 0.315 i.p. s so 3-aza-pentanamido )-5- chlor-benzophenone 2-( 5-Cyano-3-aza-hexanamido )-5-chlor-benzophenone 2-( 5-Cyano-N,3-dimethyl- L1 p.o.

3-aza-hexanamido)-5-nitrobenzophenone 2'( 5-Cyano-N,4-dimethyl-3- aza-pentanamido )-benzophenone 2(5-Cyano-3-allyl-3-azai.p. a 70 0.63 i.p. 8 6O pentanamido )-2'-5-dichlorbenzophenone 2-( 5-Cyano-N-methyl-3-n butyl-3-aza-pentanamid0 5-chlor-benzophenone aza-pentanamido)-5-nitrobenzophenone 2-(5-Cyano-N,4-dimethyl- 3-aza-pentanamido)-5- methoxy-benzophenone 2-( 5-Cyano-N,4-dimethyl- 3-aza-pentanamido )-5-methylbenzophenone 2-(4-Cyan0-N-methyl-3-azabutanamido )-5-chlor-benzophenone 2-(5Cyano-N,3-dimethyl3-aza- 8 pentanamido)-5-chlorbenzophenone 2-(5-Cyano-N,3,4-trimethylchlor-benzophenone 2-(5-Cyano-N,3-dimethyl-3- aza-pentanamido)-5-nitrobenzophenone hexanamido)-5-chlor-benz0- phenone pentanamido)-5-methoxy-benzophenone Continued g/kg (mouse) Compound Dose mg/kg Sedative action 70 [n the following examples the temperatures are given in C. The abbreviation Z in the statements of the melting points means decomposition. The sorbent used for the thin layer chromatograms was silica gel HF 254+366 (Type 60) according to Stahl. The proportions given in the case of the eluents are proportions by volume.

EXAMPLE 1 9.8 g of 3-methylamino-2-methylpropionitrile were dissolved in 100 mls. of anhydrous dioxane. A weak stream of nitrogen was passed into this solution and it was heated to boiling under reflux. A solution of 16.1 g of 2-( 2-chloro-N-methyl-acetamido )-5 chlorobenzophenone, dissolved in 150 mls. of anhydrous dioxane, was then added drop by drop whilst stirring, and the reaction mixture was heated under reflux for 4 hours. After cooling, the precipitated 3- methylamino-2-methylpropionitrile hydrochloride was filtered off under suction and the filtrate was concentrated in vacuo. The oily residue (200g) was dissolved in 300 mls. of absolute diethyl ether, filtered and the monohydrochloride of 2-(5-cyano-N,3-dimethyl-3-azahexanamido)-5-chlorobenzophenone was precipitated with dry hydrogen chloride. The yield was 18.8g, corresponding to 89% of theory. The product had a melting point of 113-115 and was analytically pure without re-crystallisation. A thin-layer chromatogram of a sample of the product showed an absence of the starting compound and the RF value of the product was 0.85 in methanol.

EXAMPLE 2 3.4 g of 2-(methylamino-acetamido)-5- chlorobenzophenone hydrochloride, 0.75 g of chloracetonitrile and 2.0 g of triethylamine were heated with agitation under reflux for 8 hours in 100 mls. of

absolute toluene. The triethylamine hydrochloride which was precipitated when the reaction mixture was cooled overnight was filtered off, and the filtrate was washed using mls. of water each time, dried over potassium carbonate, filtered and concentrated in vacuo. The 3.5 g of oily base obtained were dissolved in mls. of anhydrous ether, filtered and 2-(4-cyano- 3-methyl-3-aza-butyramido)-5-chlorobenzophenone hydrochloride with a melting point of l52154 was obtained in a yield of 3.2 g, corresponding to 84.5% of theory, by passing in dry hydrogen chloride. In a thin layer chromatogram the RF value in 2:8 cyclohexane/ethyl acetate as flow medium was 0.9.

EXAMPLE 3 3.3 g of 2-(2-Chloro-N-methyl-acetamido)-5- nitrobenzophenone, 1.2 g of 3-amino-butyronitrile hydrochloride and 2.0 of triethylamine were heated in 100 mls. of anhydrous benzene for 4 hours while stirring and boiling under reflux. After cooling to room temperature the precipitated triethylamine hydrochloride was'filtered off under suction and the filtrate was shaken three times with 100 mls. of water each time in a separating funnel, dried over potassium carbonate, filtered and concentrated in vacuo.

3.3 g of oily base obtained were dissolved in mls. of anhydrous diethyl ether, the solution was filtered, and the monohydrochloride of 2-(5-cyano-N,4- dimethyl-3-aza-pentanamido)-5-nitro-benzophenone was obtained by passing dry hydrogen chloride into the solution. The yield was 2.9 g corresponding to 70% of theory, the melting point was l29l3l, and the RF value in methanol as flow medium was 0.75.

By methods similar to those described in Examples 1, 2 and 3, the compounds set out in the following Table I were also synthesised:

in the foregoing examples is exemplified by the production, described below, of the 2-(N-mcthy1-N-Bchloropropionylamino)--chloro-benzophenone used as starting compound for example in the production of 2-(6- cyano-N,5-dimethyl-4-aza hexanamido)-5-chlorobenzophenone and 2-(6-cyano-N,4-dimethyl-4-azahexanamido)-5-chloro-benzophenone which appear in the table above, when they are produced according to the method of Example 1. 179

14.0 g of B-chloropropionyl chloride were rapidly added drop by drop to a solution of 24.6 g of 2- methylamino-5-chloro-benzophenone in 300 mls. of anhydrous toluene, the temperature rising from 18 to C. The reaction mixture was then maintained for 4 hours at an internal temperature of 80C, and then heated for a further 2 hours, with stirring, under reflux. After cooling it is filtered and unreacted B-chloropropionyl chloride was drawn off under vacuum at approx imately 0.1 mm Hg using a water bath rising to a final temperature of 90C. The oily residue was allowed to stand for 3 days in a refrigerator where it crystallised. The crystals were rubbed up with petrol ether and dried in vacuo.

Yield: 29.8 g of 2-(N-methyl-N-B-chloropropionylamino)-5-chloro-benzophenone (89% of theory) with a melting point of 7375.

chlorobenzophenone, 5.0 g of methyl aminoacetate hydrochloride and 8.0 g of triethylamine were heated under reflux in 250 mls. of absolute toluene for 6 hours whilst stirring. The precipitated triethylamine hydrochloride was filtered off under suction after cooling, the filtrate being shaken three times, with 250 mls. of water each time, in a separating funnel, and the organic phase was dried over potassium carbonate, filtered and concentrated in vacuo. The oily residue was dissolved in 300 mls. of absolute ether, filtered and converted into a 9.5 g of 2-(4-carbmethoxy-N-methyl-3-azabutyramido )-5-chlorobenzophenone hydrochloride with a melting point of ll6-118, corresponding to 58% of theory, by passing in dry hydrogen chloride gas. The RF value in a thin layer chromatogram with 1:1 cyclohexane/ethyl acetate as flow medium was 0.95.

EXAMPLE 5 A mixture of 3.4 g of 2-(methylamino-acetamido)-5- chlorobenzo-phenone hydrochloride, 1.7 g of ethyl bromacetate and 2.0 g of triethylamine was heated to boiling in mls. of absolute toluene for 8 hours whilst stirring. The triethylamine hydrochloride which was precipitated quantitatively was filtered off under suction, the filtrate was shaken three times with 100 mls. of water each time and dried over potassium car- 'into bonate. 3.2 g of oily crude base were obtained which, dissolved in 50 mls. of anhydrous ether, were converted 2-( 4-carbethoxy- 3-methyl-3-aza-butyramido chlorobenzophenone hydrochloride by passing in dry hydrogen chloride. The yield amounted to 3.5 g corresponding to 82% theory. The melting point was l77-** and the RF value in the thin layer chromatogram was 0.7 in 1:1 cyclohexane/ethyl acetate as flow medium.

diethylether and the solution was filtered. By passing dry hydrogen chloride into the solution 2.0 g of 2-(4- amidocarbonyl-3-methyl-3-aza-butyramido)-5- chlorobenzophenone hydrochloride (74% of theory) were obtained with a melting point of l63l65 (decomposes).

This product could also be obtained by dissolving 4.0 g of 2-(4-ethoxy-carbonyl-3-methyl-3-azabutyramido)-5-chlorobenzophenone hydrochloride in 8O mls. of anhydrous ethyl alcohol and whilst stirring EXAMPLE 6 at 60 to 70 introducing into the solution for 8 hours L7 g of 2 (methylamino acetamido) 5 allstreantof amrdnofniahgas, the reaction milxture being chlorobenzophenone hydrochloride, 0.85 g of ethyl a a g; $35? urt er g l Yessel bromacetate and 0.7 g of anhydrous potassium carbonan u h l Pg j y 1 tfirmg 0 precipitated ate were heated for hours under a reflux in 100 mls. i c 8 3 cailcemratmghm of anhydrous acetone whilst stirring. After cooling, the prqcee ng as escn e m e paragrap. a am1docarbonyl-3-methyl-3-aza-butanam1do)-5-chloroinorganic salt was filtered off under suction concenb enzophenone hydrochloride was obtained. Yield. 2.5 trated in vacuo, and the oily resldue was timed in vacuo.

g (68% of theory). The product possessed a melting The yield of oily crude base was 1.4 g. It was dlssolved 20 oint of 0 0 (decom OSes) in 30 mls. of absolute dioxane, the solution was filtered p p and diluted with 30 mls. absolute ether, 1.3 g of 2-(4- EXAMPLE 3 carbethoxy-3-methyl-3-aza-butyramido)-5- 4 6 g of 2-(methylam1no-acetam1do)-5- l z f gl z gl 23123323 3 gf i g chlorobenzophenone hydrochloride were heated in 5 0 hl T duct was i i withythgt 100 mls. of dry xylene with 3 g of triethylamine and 1.9

L 1 g of chloroacetic acid for 8 hours under reflux whilst O tame Xamp e stirring. After cooling, the precipitated triethylamine hydrochloride was filtered off and the filtrate was EXAMPLE 7 shaken 3 times with 100 mls. of water each time. After A mixture of g of Y drying over potassium carbonate and filtering, it was chlorobenzophenone hydr i g of ChlO- concentrated in vacuo, the oily crude base obtained racetamide and g of trlethylamme heated for 3 being dissolved in 100 mls. of dry ether and filtered hours under a reflux in 100 mls. of anhydrous xyleneagain. By passing in dry hydrogen chloride gas, filtering The triethylamine hydrochloride whlch Was pre lplunder suction and drying in a vacuum desiccator, 2.8 tated quantitatively was filtered off under suction after g (71% f th f 2 (4- b -3- h l 3 cooling and the filtrate was shaken three times with butyramido)-5-chlorobenzophenone hydrochloride mls. of water each time, the organic phase being dried were obtain d with a l i point f 162 164, over anhydrous potassium carbonate, filtered and con- B process similar to those described Examples 4 to centrated in vacuo. The oily crude base obtained as a 8, the compounds described in the following Table ll residue (2.2g) was dissolved in 100 mls. of anhydrous 40 were also produced:

..1. :2 11 co c n N c n 12 r.: co 1i\\ TABLE II R1 1| 2n R2 R3 m zm R4 R5 Melting point of hydro chloride.

H -CH,- H C0 CH, CH,- C1 H l28-l30 CH, CH,- H C0-OC,H H,C-CH,- C1 H 111-1 13 (Z) H -CH H Co-0C,H, H,C-CH, Cl H -107 (Z) CH, CH,- H COOCH, CH, N0 H 142-144" 2 CH, -CH,- H C0-0C,H -CH,-CH, CF, H 137-139 H -CH,- H CO OC,H CH,-CH,- C1 C1 129-131 CH, -CH, H C0 0C,H, -CH,-CH, N0 H 127-129 CH CH, H COOC2H5 CH2-CH- Cl H l36l38 -CH H -CH,- H C0--OC,H CH, CH- 2 N0 H 157-159 c cH, cH,- H co oc,H, c cH- No H 155457 cH, cH=cH, cH, H co oc,H, CH:CH: Cl H 116-118 2 H CH,-- CH, COOH CH CH Cl H 154-157 CH, CH,- H C0-OC..H -CH,-CH,-0CH, H 143-145 CH, -cH, H COOC,H, cH, cH,-scH H l43l45 (2 CH, -CH, H COOC2H5 CH,CH2CH, H l08lll(Z) CH, CH,- H COOC H, -CH -CH CH OCH, H 84 86 CH, CH, H CO-OC2H5 CH Cl l- 2 CH3 H lO6-l08 EXAMPLE 9 3.0 g of 2-(methylamino-acetamido)-5-chlorobenzophenone were dissolved in 30 mls. of anhydrous alcohol and then mixed with 2.0 g of freshly distilled acrylonitrile. The mixture was stirred for 2 hours at room temperature and then heated under reflux for a further 8 hours. After being allowed to stand overnight at room temperature a further 2.0 g of freshly distilled acrylonitrile was added and the mixture heated under reflux with stirring for a further 4 hours. At this point a sample showed in a thin-layer chromatogram a uniform point which differed from that of the initial product. The turbid solution was filtered and concentrated in vacuo (approx. 0.1 mm Hg), 3.0 g ofa colourless oil being obtained. This residue was dissolved in anhydrous diethylether. After passing dry hydrogen chloride into this solution 3.6 g of 2-(5-cyano-3-methyl-3- aza-pentanamido)--chloro-benzophenone hydrochloride were obtained, corresponding to 92% of theory. The product had a melting point of l66l68. The RF value in a thin-layer chromatogram in methanol as flow medium was 0.85.

The RF value and the melting point were identical with those of the product which was obtained from 2- (chloracetamido)-5-chloro-benzophenone and B-methylamino-propionitrile using a method similar to that of Example 1 (cf. th example in table in Example 3).

In an analogous manner, starting from 2- (methylamino-acetamido)-5-chloro-benzophenone and ethyl acrylate, 2-(5-ethoxycarbonyl-3-methyl-3- aza-pentanamido)-5-chlorobenzophenone hydrochloride is obtained with a melting point of 12913l, and starting from 2-(methylamino-acetamido)-5- chlorobenzophenone and acrylamide, 2-(5- amidocarbonyl-3-methyl-3-aza-pentanamido )-5- chloro-benzophenone hydrochloride is obtained with a melting point of l58l60.

The 2-(methylamino-acetamido)-5-chlorobenzophenone required as starting compound was produced as follows:

A solution of 24.5 g of 2-(chloracetamido)-5- chlorobenzophenone in 400 mls, of anhydrous dioxane was mixed with 150 mls. of a solution of methylamine in methyl alcohol and was then allowed to stand at room temperature overnight in a closed vessel. The reaction mixture was then filtered and the filtrate is concentrated in vacuo at a waterbath temperature of the residue being shaken with 630 mls. of diethyl ether and 700 mls. of 0.3N hydrochloride acid. The ether layer was shaken out once again with 250 mls. of 0.3N hydrochloric acid and the combined hydrochloric acid extracts were rendered alkaline with concentrated aqueous ammonia whilst cooling thoroughly, and were then extracted with methylene chloride; the methylene chloride phase was dried over potassium carbonate. After drying the methylene chloride solution was filtered and concentrated in vacuum. The oily crude base obtained as a residue, after drying, was dissolved in 100 mls. of anhydrous diethyl ether, filtered and converted by the introduction of dry hydrogen chloride into 23.8 g of 2-(methylamino-acetamido)-5- chlorobenzophenone hydrochloride (88% of theory), melting point l99-20l.

EXAMPLE 10 2.1 g of sodium bisulphite were dissolved in 15 mls. of water and mixed drop by drop at l520C with 1.8

g of 40% formaldehyde solution, the stirring being continued for 30 minutes and then 3.0 g of 2- (methylamino-acetamido)-5-chlorobenzophenone were added to the reaction mixture. Then whilst stirring a solution of 1.3 g of potassium cyanide in 3 mls. of water was added drop by drop and the mixture stirred for 3 hours at 40C. After being allowed to stand overnight at room temperature, the semi-solid reaction product was filtered off under suction, shaken up several times with water, and dried in a vacuum desiccator. From a solution of 2.4 g of the crude base in Y mls. of anhydrous diethyl ether, 2.8 g of 2-(4-cyano-3- methyl-3-aza-butanamido)-5-chloro-benzophenone hydrochloride (74% of theory) with a melting point of l53l55 were obtained by passing in dry hydrogen chloride.

The melting point and the RF value in a thin-layer chromatogram (0.9) correspond with those of the product obtained in Example 2.

What is claimed is: g 7

l. Benzophenone derivatives having the structural formula and the acid addition salts thereof, wherein R, and R are substituents selected from the group consisting of hydrogen, allyl and alkyl having 1 to 4 carbon atoms; R is CN; n is an integer selected from 1 and 2; and m is an integer selected from 1, 2 and 3, and wherein the ring A is selected from the group consisting of phenylene, halogenphenylene, nitrophenylene, trifluoromethylphenylene, methylphenylene, methoxyphenylene and methylmercaptophenylene; the ring B is selected from the group consisting of phenyl, fluorophenyl and chlorophenyl.

2. Benzophenone derivatives according to claim 1, and the pharmaceutically acceptable acid addition salts thereof, wherein the ring A is substituted at the 5 position and the ring B is substituted at the 2 position.

3. Benzophenone derivatives according to claim 1, and the pharmaceutically acceptable acid addition salts thereof, wherein R is a substituent selected from the group consisting of hydrogen and methyl and R is a substituent selected from the group consisting of hydrogen, methyl and butyl.

4. 2-(5-Cyano-N,4-dimethyl-3-aza-pentanamido)-5- chlorobenzophenone, and pharmaceutically accept ceutically acceptable acid addition salts thereof.

2-(5-Cyano-N-methyl-3- n-butyl-3-aza- UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 5,888,899 Dated June 975 Inventor( Heinz Gunter Greve et a1.

It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column l i, Claim 1, the formula should read as follows:

1 B2 g n 1 iii g N m .311 m {if n 1, 115

Signed and Scaled this Fourteenth Day of September 1976 [SEAL] Arrest:

RUTH c. MASON c. MARSHALL DANN Arresting Officer Commissioner uj'Paienis and Trademarks 

1. BENZOPHENONE DERIVATIVES HAVING THE STRUCTURAL FORMULA
 2. Benzophenone derivatives according to claim 1, and the pharmaceutically acceptable acid addition salts thereof, wherein the ring A is substituted at the 5 position and the ring B is substituted at the 2'' position.
 3. Benzophenone derivatives according to claim 1, and the pharmaceutically acceptable acid addition salts thereof, wherein R1 is a substituent selected from the group consisting of hydrogen and methyl and R2 is a substituent selected from the group consisting of hydrogen, methyl and butyl.
 4. 2-(5-Cyano-N,4-dimethyl-3-aza-pentanamido)-5-chlorobenzophenone, and pharmaceutically acceptable acid addition salts thereof.
 5. 2-(5-Cyano-N,3-dimethyl-3-aza-hexanamido)-5-nitrobenzophenone, and pharmaceutically acceptable acid addition salts thereof.
 6. 2-(5-Cyano-N,4-dimethyl-3-aza-pentanamido)-benzophenone, and pharmaceutically acceptable acid addition salts thereof.
 7. 2-(5-Cyano-3-allyl-3-aza-pentanamido)-2''-5-dichlorobenzophenone, and pharmaceutically acceptable acid addition salts thereof.
 8. 2-(5-Cyano-N-methyl-3-n-butyl-3-aza-pentanamido)-5-chloro-benzophenone, and pharmaceutically acceptable acid addition salts thereof. 